The Viking E-40 Satin White Entry Phone is compact, weather and vandal resistant, telephone line powered speaker phone designed to provide two-way handsfree communication. The compact size allows it to be mounted in a standard single gang electrical box. Its blue LED continually provides light for locating the push button in dark locations, dims to indicate off hook and flashes during incoming ring. The E-40 Polished Brass Finish entry phone can share a single phone line with house or small business telephones when used with a Viking model C-200, C-250 or C-2000B Entry Phone controller. The E-40 Polished Brass Finish entry phone can also be connected to an unused analog station port (programmed for ring down) on a phone system or connected directly to a telephone line when used with a Viking model K-1900-5 or K-1900-30 auto dialer.It features microphone and speaker volume controls, selectable auto answer for monitoring and intelligent call progress detection for automatic hang-up when the call is completed. Compact Size Front panel is the size of a typical single gang midsize wall plate. Mounting Flush mounts in a single gang electrical box (2.25 deep x 2 wide x 2.84" tall minimum) or surface mounts in a Viking model VE-3x5. Vandal Resistant Features 16 gauge polished brass faceplate, 316 stainless steel push button, carbon fiber reinforced plastic speaker screen, scratch resistant powder coating, hex drive mounting screws. Weather Resistant Features Mylar speaker, faceplate gasket, mic and speaker gasket, internally sealed (IP67) push button switch, self draining mic mount and UV stable weather resistant powder coating.